A damaging effect of manganese on fabrics during bleaching has been known since the 19th century. In the 1960's and 1970's, efforts were made to include simple Mn(II) salts in detergents, but none saw commercial success. More recently, metal-containing catalysts containing macrocycle ligands have been described for use in bleaching compositions. Preferred catalysts include those described as manganese-containing catalysts of small macrocycles, especially the compound 1,4,7-trimethyl-1,4,7-triazacyclononane. These catalysts assertedly catalyze the bleaching action of peroxy compounds against various stains. Several are said to be effective in washing and bleaching of substrates, including in laundry and cleaning applications and in the textile, paper and wood pulp industries. However, such metal-containing bleach catalysts, especially these manganese-containing catalysts, still have shortcomings, for example a tendency to damage textile fabric, relatively high cost, high color, and the ability to locally stain or discolor substrates.
Salts of cationic-metal dry cave complexes have been described (in U.S. Pat. No. 4,888,032, to Busch, Dec. 19, 1989) as complexing oxygen reversibly, and are taught as being useful for oxygen scavenging and separating oxygen from air. A wide variety of ligands are taught to be usable, some of which include macrocycle ring structures and bridging groups. See also: D. H. Busch, Chemical Reviews (1993), 91, 847-880, for example the discussion of superstructures on polydentate ligands at pages 856-857, and references cited therein; B. K. Coltrain et al., "Oxygen Activation by Transition Metal Complexes of Macrobicyclic Cyclidene Ligands" in "The Activation of Dioxygen and Homogeneous Catalytic Oxidation", Ed. by E. H. R. Barton, et al. (Plenum Press, NY; 1993), pp.359-380.
More recently the technical literature on azamacrocycles has grown at a rapid pace. Among the many references are Hancock et al., J. Chem. Soc. Chem. Commun. (1987), 1129-1130; Weisman et al., "Synthesis and Transition Metal Complexes of New Cross-Bridged Tetraamine Ligands", Chem. Commun. (1996), 947-948; U.S. Pat. Nos. 5,428,180, 5,504,075, and 5,126,464, all to Burrows et al.; U.S. Pat. No. 5,480,990, to Kiefer et al.; and U.S. Pat. No. 5,374,416, to Rousseaux et al. None of hundreds of such references identify which of numerous new ligands and/or complexes would be commercially useful in bleaching compositions. This history does not reveal the possibility that catalytic oxidation may alter almost all families of organic compounds to yield valuable products, but successful application as hard surface or fabric bleaching depends on a complex set of relationships including the activity of the putative catalyst, its survivability under reaction conditions, its selectivity, and the absence of undesirable side reactions or over-reaction.
In view of the long-felt need, the ongoing search for superior bleaching compositions containing transition-metal bleach catalysts, and in view of the lack of commercial success to this point, especially in fabric laundering compositions with transition-metal bleach catalysts; in view also of the ongoing need for improved cleaning compositions of all kinds which deliver superior bleaching and stain removal without disadvantages such as tendency to damage or discolor the material to be cleaned, and in view also of the known technical limitations of existing transition-metal bleach catalysts for detergent applications, especially in aqueous solutions at high pH, it would be very desirable to identify which of thousands of potential transition-metal complexes might successfully be incorporated in laundry and cleaning products. Accordingly it is an an object herein to provide superior cleaning compositions incorporating selected transition-metal bleach catalysts with detergent or cleaning adjuncts that resolve one or more of the known limitations of such compositions.
It has now surprisingly been determined that, for use in laundry and hard-surface cleaning products, transition-metal catalysts having specific cross-bridged macropolycyclic ligands have exceptional kinetic stability such that the metal ions only dissociate very slowly under conditions which would destroy complexes with ordinary ligands, and further have exceptional thermal stability. Thus, the catalysts useful in the present invention compositions can provide one or more important benefits. These include improved effectiveness of the compositions, and in some instances even synergy with one or more primary oxidants such as hydrogen peroxide, hydrophilically or hydrophobically activated hydrogen peroxide, preformed peracids, or monopersulfate; the cleaning compositions include some especially those containing Mn(II), in which the catalyst is particularly well color-matched with other detergent ingredients, the catalyst having little to no color. The compositions afford great formulation flexibility in consumer products where product aesthetics are very important, and are effective on many types of soils and soiled substrates, including a variety of soiled or stained fabrics or hard surfaces. The compositions permit compatible incorporation of many types of detergent adjuncts, including hydrophobic bleach activators, with excellent results. Moreover, the compositions reduce or even minimize tendency to stain or damage such surfaces.
These and other objects are secured herein, as will be seen from the following disclosures.